Self-steering trailer.



w. L, DAHL. SELF STEERING TRAILER. APPLICATION FILED APR. 22, l9\8 ou 1 m Gus 1 vn 0 N m R 0U In a D..

2 SHEETS-SHEET w.` L. DAHL. SELF STEERING TRAILER.

APPLICATION FILED APR.22, T918.

l Patented Nov. 19, 1918.

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WALTER L. DAHL, 0F COKATO, MINNESOTA.

` SELF-STEERING TRAILER.

To all whom t may concern:

Be it known that I, WALTER L. DAHL, a citizen of the United States, residing at Cokato, in the county of Wright and tate of Minnesota, have invented certain new and useful Improvements in Self-Steering Trailers; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention has for its object to provide an improved steering mechanism for socalled self-steering trailers; and to such ends generally stated, the invention consists of the novel devices and combinations of devices hereinafter described and defined in the claims.

rlhe term trailer is herein used in a broad and liberal sense to include any ln'nd of a wheeled vehicle that is trailed behind an automobile or motor propelled lead vehicle. Two important applications of the invention are; a, for drawing a two-wheeled trailer at the rear of an automobile; and b, for drawing one or more automobiles as trailers at the rear of a lead automobile.

1n the accompanying drawings which illustrate the invention, like characters indicate like parts throughout the several views.

Referring to the drawings:

Figure 1 is a plan view of the running gear and steering mechanism of the trailer;

Fig. 2 is ya rear elevation of the parts shown in Fig. 1;

Fig. 3 is a'vertical section taken onpthe line 3-3 of Fig. 1;

Fig. 4 is a view chiefly in plan but with some parts in section, illustrating the steering connection applied to the front axle of a rear vehicle;

Fig. 5 is a rear elevation of the parts shown in Fig.'4;

Fig. 6 is a section on the line 6-6 of Fig. 4, some parts being broken away;

Fig. 7 is an enlarged section taken approximately on the line 7 7 of Fig. 4; and

Fig. 8 is a transverse section on the line 8-8 of Fig. 7.

Referring first to the arrangement illustrated in Figs. 1, 2 and 3, the running gear comprises .a rear axle 4. having a rigidly connected forwardly projecting reach bar 5, preferably in the form of a metal tube or pipe. Brace rods 6 connect the intermediate portion of the reach 5 to the end portions ipeoition 0f Letters Patent.

Application led April 22, 1918.

Patented Nov. 19, 1918.

seria1 No. 230,147.

12. A crank rod 13 is pivotally connectedl to oneof the arms 9 at its outer end, and at its lnner end is pivotally connected to the depending arm 12. The pivotal connection between the rod 13 and arm 12 is preferably made adjustable by means of a plurality of holes in said arm, into any one of'which the coupling pin or bolt 14 of the said pivotal connection may be applied.

A cast yoke 15 is rigidly securedjto the front end of the tubular reach 5, and the front end of this yoke, by means of a vertical coupling pin 16, is pivotally connected to a forked head 17. This forked head 17, by means of a horizontal nut-equipped swivel bolt 18, is connected to a bearing 19, which, in turn, is rigidly secured to the central portion of a strap-like anchor bracket 20. At its ends, the bracket 2O has forwardly projected perforated ears, to which pronged clamping brackets 21 are pivotally connected at 22. These clamping brackets 21 are adapted to be secured around the rear axle casing of an automobile. For thus securing the brackets 21 to the rear axle casing, short nut-equipped bolts 23 are applied to the perforated ends thereof. Of course. any other suitable means may be employed for securing the anchor bracket 20 to the rear axle or other suitable rear portion of the automobile.

The upper ange of the forked head 17 1s extended and made in the form of a bevel gear segment 24, that meshes with abevel pinion 25, which latter is located within the yoke 15 and is rigidly secured to the front end of the rock shaft 11.

The body of the trailer will, of course, be carried from the running gear in the usual or any suitable way, not necessary for the purposes of this case, to consider.

In the operation, the anchor bracket 20 will partake of the angular movements of the rear axle of the automobile and when the automobile is turned over toward the right or toward the lett the segmental gear acting on. the bevel gear 25 will roch the shaf ll in the proper direction to cause the crank arm l2 and rod 13 to oscillate the wheels 8 in the proper direction to cause the said wheels 8 to trail the rear wheels ci' the automobile, or, in other words, to run in approximately the same tracks. The ad justinent ot the pivotal connection between the arm l2 and rod 13 provides for the regulation of the steering action to cause the proper trailing oit the trailer wheels with the wheels of the automobile.

The pivotal connection ot the pin le, of course, permits the above described nieveinent of the gear 2i, and the necessary angular movement ci the reach 5. The swivel connection on the bolt l@ permits the rear wheels to adaptthemselves to irregularities of the road bed, or, in other words, permits the running gear ci the trailer to oscillate troni side to side without putting the strain on the comiections between the trailer and the automobile. lreierably, the separation between the trailer and the automobile will be made by removing the coupling,1 bolts 22, but it might he roade by removing' the swivel bolt i8.

ldeierring now to the arrangement illustrated in lligs. Li to d, inclusive, the iront portion ci the coupling device, to wit, the

gear and piston connection 2lb-25 and coupling;l brackets, may be the same as that above described, but in this arrangement, the rear end ci the coupling' and steering device is applied to the iront aine oi a rear vehicle or automobile.

la indicates the trent axle ot the said rear vehicle, such as an automobile that is being towed, 8a the liront wheels, la the pivotal aale, 9a` the arms from said ,trunniona and 10a the transverse rod that connects the arrn 93. ln this rnodied arrangement, the reach 3a is made up o' telescoped tubes, the rear end oi3 the rear section thereo3 being connected by split clamp 26a, or the lilre, to a transverse hinge rod 2li, which latte as shown, is in the o a tube. The ends ot the hinge rod Q6 are pivoted in splits clamping brackets 95'?, which, by means el nut-equipped bolts le', are rigidly but detacliably clamped to the i'ront axle la ot the said rear vehicle. The hinge aiorded by the rod 26 permits the wheels ol the lead and trailing automobiles to adapt themselves to irregular roads and to runninge,q over crowns or elevations, and the lilre.v rlhe hinge rod 526 is further connected to the liront end ci the rear section oi the extensible reach 3B by means ol? brace rods 28. Also, in this construction, the shalt that connects the pinion to the crank l2 is roads longitudinally ostensible and is composed of two telescopi sections lland ldy ineens lrey d lreyway or other sliding` engagement, the shalt sections lla and lll are caused to rotate together. 'lo allord a suitable bearing in the cylindrical rear erid 'o' the shalt section 1lb (see Fig. d), a bearing plug 2@ is inserted in the rear end of the rear section of the telescopic reach 3a.

The steering action oi this last 'described arrangement is the saroe as that ci' the .lilrst. ln soins vehicles, the arms from the asie trunnions project forward of the iront axle, and in such construction, the crank l2 should be set upward instead ci downward. rlhis setting otn the crank may be easily adjusted in several ways, preferably by simply removing the pin i6, turning the shalt and cranlr through 180 degrees, then 11e-applying the pin le with the pinion 25 properly engagged with the segmental gear 2e. lor locking the sections ot the telescopically extensible reach 3a in its set adjustnient, a set screw 30, (see lqiff 7), or any other suitable device may be provided.

The device last described will be `looted highly desirable for trailing one or more automobiles behind a lead machine. Such devices are especially desired at this time because ot the diculty or impossibility oi .securinc' cars for the shipment of automobiles. elh'e diculty of securing cars has made it a common practice to drive cars :trom the `aotory to points hundreds ofc' miles distant troni the lace or manu-lecture. There is, or1 course, great economy in labor in drawing one or more cars lroei the lead car, which rnay be run by one man.

The device lastdescribed is highly ecient -lor the latter noted purpose. lt is also important .to note "hat the reach to the shaiit may be lengthened or shortened, as required to properly propel cars of different maire and that will be done without intertering. with the adiustnients ol the automobile steering niechacis From the foregoing, it willbe understood that the terre. trailer is used in a sense broad enough to include either a trailing cart or an ordinary automobile drawn at the rear ot a lead machine.- lWhen the coupling and steering mechanism is applied, as shown in d, the reach 3a bears the same relation to the bearing axle of the rear vehicle that it does to the axle ot the two-wheeled trailer illustrated in VFigs. l, 2 and '3, and may, therefore, be treated as the reach of the trailer or trailing vehicle.

The device described can be made at cornparatively small cost .and is highly ecient lio-fthe purposes had in view.

l claim is:

l. The combination with the running gear ci" a trailer, ci' a roclr shait extending along the reach thereof, a crank connection between the rear end o-E said roeli shaiit and the trailer wheels, an anchoring device or connection to the rea-r portion of an automobile, and a gear connection between said anchoring device and the front end of said rockl shaft. y

2. The combination with the running ear of a trailer, of a rock shaft extending a ong the reach thereof, a crank connection between the rear end of said rock shaft and the trailer Wheels, an anchoring device for connection to the rear portion of anl automo# bile, and a gear connection between said anchoring device and the front end of said rock shaft, the said connections including a longitudinal swivel for permitting the trailer wheels to adapt themselves to irregularities in the road.

3. The combination with the running ea-r of a trailer truck, said running gear inc uding a reach, of a .yoke secured to the front end of said reach, an anchoring bracket having a head pivotally connected to said yoke by a vertical pivot, a rock shaft mounted on said reach, a bevel gear located within said yoke and secured to the front end of said rock shaft, a bevel gear meshing with said first. noted bevel gear and mounted for `horizontal movements with said coupling bracket, a crank arm secured to the rear end of said rock shaft, means connecting the wheels of the truck for parallel oscillatory movements, and a crank crank arm to said wheel connections.

rod connecting said Y l. A combined coupling and steering des v vice for causing one vehicle to trail another, comprising a reach having means at its front end for connection to the rear portion of a lead vehicle, and having means at its rear end for connecting the same to the axle of a vehicle to be drawn, a rock shaft extended along said reach, a gear connection at the front end of said rock shaft, a crank at the rear end of said rock shaft, and a crank rod connected tosaid crank and having means for connection to the transverse steering rod of the rear vehicle.

In testimony whereof I ax my signature in presence of two witnesses,

WALTER L. :ll-` 

